1. Field of the Invention
The disclosures herein generally relate to communication apparatuses, communication methods, and programs, and particularly relate to a communication apparatus, communication method, and program which have an energy saving mode.
2. Description of the Related Art
Various types of electronic devices are designed to reduce power consumption by entering an operation state referred to as a minimum power state, an energy saving state, a power saving state, or the like (which will hereinafter be referred to as a “power saving state”) when no operational input is given for a sustained period. Such electronic devices exit a power saving state to enter a normal operating state (hereinafter referred to as a “normal power state”) in response to the inputting of operational instruction.
An electronic device with communication function (hereinafter referred to as a communication apparatus) may be designed to respond to a received packet. Frequency of packet reception is generally higher than the frequency of operational instruction entered by users. If recovery to a normal power state is performed each time a packet is received in a power saving state, it becomes difficult to effectively reduce power consumption. In consideration of this, communication apparatus hardware may be divided into a main system and a sub system, thereby prolonging the duration of power saving state.
The main system hardware may include a main CPU that controls the functions of the apparatus. The sub-system hardware may include a sub CPU that controls communication in the power saving state. Power consumption by the sub system is significantly lower than power consumption by the main system. When the communication apparatus enters a power saving state, the supply of power to the main system is suspended or reduced, and the sub system processes received packets. With such a configuration, it is possible to prolong the duration of the no-operation state (i.e., power saving state) of the main system.
Conventionally, tasks performed by the sub system (i.e., the responsibility of the sub system) are limited to simple, routine tasks such as a response to an ARP (Address Resolution Protocol) request, a response to PING, etc. Depending on how the communication apparatus is used by users, thus, there may be a case in which power consumption is not effectively achieved.
Specifically, the communication apparatus may be an image forming apparatus to which application and communication control modules can be freely added, for example. When an application or communication control module is newly installed, the frequency of the apparatus returning to a normal power state may be increased due to the installation. Namely, the installed application or communication control module performs communication that may increase the frequency of reception of packets that are outside the area of responsibility of the sub system. As a result, the main system may exit the power saving state more often. Further, there may be additional conditions for recovery or processes for adequate recovery due to the added application or communication control module.
An installed application or the like may differ depending on how the communication apparatus is used by users, and is thus difficult to predict in advance. This makes it difficult for a conventional fixed sub-system to cope.
Accordingly, it may be preferable to provide a communication apparatus, a communication method, and a program that can properly maintain a power saving state.